[poppler] gfile.cc fails to build on macos due to statbuf.st_mtim

[suzuki toshiya]

Hi,

It seems that the counterpart in macOS libc corresponding to
stat.st_mtim is stat.st_mtimespec.
https://opensource.apple.com/source/xnu/xnu-201.5/bsd/sys/stat.h.auto.html

I wrote a patch testing st_mtim availability by CHECK_STRUCT_HAS_MEMBER()
suggested by William, and also testing st_mtimespec too, and reflect
the result to the macro GET_MTIM_FROM_STATBUF().
https://github.com/mpsuzuki/poppler/commit/79d00ac08d672d572a7ec310b5a27eb66c956e4c

Building on travis-ci.org finishes successfully. Yet I'm
unsure such macro is following to the coding style of poppler.
Also if anybody has a testing code to evaluate the code works
well (do you have to make 2 file with nsec difference of the
timestamp?). Please give me comment...

Regards,
mpsuzuki

On 2/19/2018 1:42 PM, William Bader wrote:
> Can you test for it in cmake? https://cmake.org/cmake/help/v3.0/module/CheckStructHasMember.html
> 
> ________________________________
> From: poppler <poppler-bounces at lists.freedesktop.org> on behalf of Jeroen Ooms <jeroen at berkeley.edu>
> Sent: Sunday, February 18, 2018 6:29 PM
> To: Ihar Filipau
> Cc: poppler at lists.freedesktop.org
> Subject: Re: [poppler] gfile.cc fails to build on macos due to statbuf.st_mtim
> 
> On Mon, Feb 12, 2018 at 3:04 PM, Ihar Filipau <thephilips at gmail.com> wrote:
>> On 2/12/18, Jeroen Ooms <jeroen at berkeley.edu> wrote:
>>> On Sun, Feb 11, 2018 at 12:11 PM, Albert Astals Cid <aacid at kde.org> wrote:
>>>> You're never assigning to tv_nsec in there but still use it in a
>>>> comparison,
>>>> that needs fixing.
>>>
>>> You are right. I think we should compare modification time only by
>>> seconds. The standard definition of 'struct stat' only specifies
>>> st_ctime, so I don't think there is a portable way to get nanoseconds:
>>> http://pubs.opengroup.org/onlinepubs/009695399/basedefs/sys/stat.h.html
> 
>>
>> That's an old version of POSIX. Check the newer version:
>>
>> http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_stat.h.html
> 
>>
>> IOW, there is a standard portable way - since 2008, 10 years ago. It's
>> just Mac OS X hasn't updated its POSIX support after v6, from
>> 2004.
> 
> OK so how do you suggest this should be fixed? It would be great if
> things would keep working on Mac OS.
> 
>